190gr to heavy for a 1:12?

[Genius.]

I found a few box's of 190gr SMK's and wonder if they will work for my rifle with a 1:12 twist, or if I should pass them down the line.


Also, I found some old, and I mean really old 168gr SMK's. Are the old ones the same as currant production?

 

[ChrisGarrett]

190gr is getting up there for a 1:12" twist, especially if you're not shooting at elevation and at sea level.

Chris

 

[ksthomas]

You should be fine in most situations, but you're getting down to the ragged edge if you are shooting in "worst case" scenarios. The 190s are usually recommended to be used with a 1x11", but you'll probably get away with it in most situations.

As for the 168s, they haven't changed in decades. Just how old are these? Sedalia address? Sante Fe Springs address? If they're really old, they'd be listed as Harris Machine Tool Co., and have a Whittier, CA, address on the box, but I'm not entirey sure they ever made the 168s under the Harris name.

 

[Bob 964]

Please note the link to an Excel spreadsheet version of Don Miller's twist formula in the following:

http://www.accurateshooter.com/technical-articles/calculating-bullet-rpm-spin-rates-stability/

 

[1lnbrdg]

I've shot the 190's in a factory 1/12 twist Remy barrel at Houston, about as close to sea level as you can get, worked fine.

 

[chariotdriver]

Shot thousands of those from my 1:12 M-86...........really the only thing it has shot. Many varmints taken past the 1000yd mark with it. The next bbl will be 1:10 though, the new bullets are just too good to pass up. The 190 VLD type need a little tighter twist.